The mating rituals of insane squirrels (thing)

This incident took place on the VassarCollege campus, but I've heard that squirrels at other colleges are just as crazy.

The squirrels here are insane. I can see two of them on the far end of this field, the first one racing toward the towering oak tree in front of it and the other one speeding after it in pursuit. Will the second one ever catch the first? And if it does, what will happen? I suppose this could be some sort of a mating ritual, but it seems a little too frenzied for that. Perhaps they have already gone through the romantic part where one squirrel takes the other out to a cozy cafe and woos it with flowers and a bottle of red wine. Yes, these squirrels must be past that point now and ready to consummate their affection for each other. One of the squirrels is, at least.

The first squirrel -- I'll call her Betty -- has finally reached the tree and begun to run up it, but she has paused about two feet up from the ground. She is turned upside-down now, tail poking up into the air like a question mark. It seems that Betty is not so intent on escaping the other squirrel -- I'll call him Philip -- as I first imagined. This must be her own literal version of playing hard-to-get. She certainly is that; I'm sure I couldn't catch her if I tried. Or maybe she wants to test Philip's physical endurance: if he can run for a longer time than she can, he can have her. Physical strength is probably an important trait to a squirrel.

Philip has now reached the base of the tree, and Betty is running again. They race along the vertical trunk of the tree just as easily as they traversed the flat ground before. Using this newly acquired dimension to her advantage, Betty does not run straight up, but spirals up the tree like one of those gigantic glass gumball machines in reverse. Philip, being a squirrel, does not have the brains to simply run straight up and catch her on one of her trips around the trunk; instead, he follows her spiral path. Now they have reached the branches, and I can't quite keep track of where they are anymore. Every few seconds I see a commotion in the shiny green leaves and I'll glimpse a flash of gray fur. One of them is chirping now. It's a sound I thought only birds made, but apparently flirting squirrels do it too.